驱动学习笔记-lcd

#include <linux/module.h>#include <linux/kernel.h>#include <linux/errno.h>#include <linux/string.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/delay.h>#include <linux/fb.h>#include <linux/init.h>#include <linux/dma-mapping.h>#include <linux/interrupt.h>#include <linux/workqueue.h>#include <linux/wait.h>#include <linux/platform_device.h>#include <linux/clk.h>#include <asm/io.h>#include <asm/uaccess.h>#include <asm/div64.h>#include <asm/mach/map.h>#include <asm/arch/regs-lcd.h>#include <asm/arch/regs-gpio.h>#include <asm/arch/fb.h>static int s3c_lcdfb_setcolreg(unsigned int regno, unsigned int red,     unsigned int green, unsigned int blue,     unsigned int transp, struct fb_info *info);struct lcd_regs {unsigned longlcdcon1;unsigned longlcdcon2;unsigned longlcdcon3;unsigned longlcdcon4;unsigned longlcdcon5;    unsigned longlcdsaddr1;    unsigned longlcdsaddr2;    unsigned longlcdsaddr3;    unsigned longredlut;    unsigned longgreenlut;    unsigned longbluelut;    unsigned longreserved[9];    unsigned longdithmode;    unsigned longtpal;    unsigned longlcdintpnd;    unsigned longlcdsrcpnd;    unsigned longlcdintmsk;    unsigned longlpcsel;};static struct fb_ops s3c_lcdfb_ops = {.owner= THIS_MODULE,.fb_setcolreg= s3c_lcdfb_setcolreg,.fb_fillrect= cfb_fillrect,.fb_copyarea= cfb_copyarea,.fb_imageblit= cfb_imageblit,};static struct fb_info *s3c_lcd;static volatile unsigned long *gpbcon;static volatile unsigned long *gpbdat;static volatile unsigned long *gpccon;static volatile unsigned long *gpdcon;static volatile unsigned long *gpgcon;static volatile struct lcd_regs* lcd_regs;static u32 pseudo_palette[16];/* from pxafb.c */static inline unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf){chan &= 0xffff;chan >>= 16 - bf->length;return chan << bf->offset;}static int s3c_lcdfb_setcolreg(unsigned int regno, unsigned int red,     unsigned int green, unsigned int blue,     unsigned int transp, struct fb_info *info){unsigned int val;if (regno > 16)return 1;/* 用red,green,blue三原色构造出val */val  = chan_to_field(red,&info->var.red);val |= chan_to_field(green, &info->var.green);val |= chan_to_field(blue,&info->var.blue);//((u32 *)(info->pseudo_palette))[regno] = val;pseudo_palette[regno] = val;return 0;}static int lcd_init(void){/* 1. 分配一个fb_info */s3c_lcd = framebuffer_alloc(0, NULL);/* 2. 设置 *//* 2.1 设置固定的参数 */strcpy(s3c_lcd->fix.id, "mylcd");s3c_lcd->fix.smem_len = 240*320*16/8;s3c_lcd->fix.type     = FB_TYPE_PACKED_PIXELS;s3c_lcd->fix.visual   = FB_VISUAL_TRUECOLOR; /* TFT */s3c_lcd->fix.line_length = 240*2;/* 2.2 设置可变的参数 */s3c_lcd->var.xres           = 240;s3c_lcd->var.yres           = 320;s3c_lcd->var.xres_virtual   = 240;s3c_lcd->var.yres_virtual   = 320;s3c_lcd->var.bits_per_pixel = 16;/* RGB:565 */s3c_lcd->var.red.offset     = 11;s3c_lcd->var.red.length     = 5;s3c_lcd->var.green.offset   = 5;s3c_lcd->var.green.length   = 6;s3c_lcd->var.blue.offset    = 0;s3c_lcd->var.blue.length    = 5;s3c_lcd->var.activate       = FB_ACTIVATE_NOW;/* 2.3 设置操作函数 */s3c_lcd->fbops              = &s3c_lcdfb_ops;/* 2.4 其他的设置 */s3c_lcd->pseudo_palette = pseudo_palette;//s3c_lcd->screen_base  = ;  /* 显存的虚拟地址 */ s3c_lcd->screen_size   = 240*324*16/8;/* 3. 硬件相关的操作 *//* 3.1 配置GPIO用于LCD */gpbcon = ioremap(0x56000010, 8);gpbdat = gpbcon+1;gpccon = ioremap(0x56000020, 4);//写4 其实写多少都没关系gpdcon = ioremap(0x56000030, 4);gpgcon = ioremap(0x56000060, 4);    *gpccon  = 0xaaaaaaaa;   /* GPIO管脚用于VD[7:0],LCDVF[2:0],VM,VFRAME,VLINE,VCLK,LEND */*gpdcon  = 0xaaaaaaaa;   /* GPIO管脚用于VD[23:8] */*gpbcon &= ~(3);  /* GPB0设置为输出引脚 */*gpbcon |= 1;*gpbdat &= ~1;     /* 输出低电平  背光不开 */*gpgcon |= (3<<8); /* GPG4用作LCD_PWREN *//* 3.2 根据LCD手册设置LCD控制器, 比如VCLK的频率等 */lcd_regs = ioremap(0x4D000000, sizeof(struct lcd_regs));/* bit[17:8]: VCLK = HCLK / [(CLKVAL+1) x 2], LCD手册P14 *    查看内核信息得到HCLK 命令 dmsg 中 S3C244x: core 400.MHz memory 100.000MHz 中memory对应的就是HCLK VCLK 看LCD手册  P14 clock cycle time 100 ns 可以慢 ,不可快clock low level width  最低 //ns -9次方时序图上也有 不过需要计算 //MMODE未设置 10MHz(100ns) = 100MHz / [(CLKVAL+1) x 2] *            CLKVAL = 4 * bit[6:5]: 0b11, TFT LCD * bit[4:1]: 0b1100, 16 bpp for TFT  RGB 565  * bit[0]  : 0 = Disable the video output and the LCD control signal. */lcd_regs->lcdcon1  = (4<<8) | (3<<5) | (0x0c<<1);#if 1/* 垂直方向的时间参数 * bit[31:24]: VBPD, VSYNC之后再过多长时间才能发出第1行数据 *             LCD手册 T0-T2-T1=4 *             VBPD=3 * bit[23:14]: 多少行, 320, 所以LINEVAL=320-1=319 * bit[13:6] : VFPD, 发出最后一行数据之后，再过多长时间才发出VSYNC *             LCD手册T2-T5=322-320=2, 所以VFPD=2-1=1 * bit[5:0]  : VSPW, VSYNC信号的脉冲宽度, LCD手册T1=1, 所以VSPW=1-1=0 */lcd_regs->lcdcon2  = (3<<24) | (319<<14) | (1<<6) | (0<<0);/* 水平方向的时间参数 * bit[25:19]: HBPD, VSYNC之后再过多长时间才能发出第1行数据 *             LCD手册 T6-T7-T8=17 *             HBPD=16 * bit[18:8]: 多少列, 240, 所以HOZVAL=240-1=239 * bit[7:0] : HFPD, 发出最后一行里最后一个象素数据之后，再过多长时间才发出HSYNC *             LCD手册T8-T11=251-240=11, 所以HFPD=11-1=10 */lcd_regs->lcdcon3 = (16<<19) | (239<<8) | (10<<0);/* 水平方向的同步信号 * bit[7:0]: HSPW, HSYNC信号的脉冲宽度, LCD手册T7=5, 所以HSPW=5-1=4 */lcd_regs->lcdcon4 = 4;#elselcd_regs->lcdcon2 =S3C2410_LCDCON2_VBPD(5) | \S3C2410_LCDCON2_LINEVAL(319) | \S3C2410_LCDCON2_VFPD(3) | \S3C2410_LCDCON2_VSPW(1);lcd_regs->lcdcon3 =S3C2410_LCDCON3_HBPD(10) | \S3C2410_LCDCON3_HOZVAL(239) | \S3C2410_LCDCON3_HFPD(1);lcd_regs->lcdcon4 =S3C2410_LCDCON4_MVAL(13) | \S3C2410_LCDCON4_HSPW(0);#endif/* 信号的极性  * bit[11]: 1=565 format * bit[10]: 0 = The video data is fetched at VCLK falling edge * bit[9] : 1 = HSYNC信号要反转,即低电平有效  * bit[8] : 1 = VSYNC信号要反转,即低电平有效  * bit[6] : 0 = VDEN不用反转 * bit[3] : 0 = PWREN输出0 * bit[1] : 0 = BSWP * bit[0] : 1 = HWSWP 2440手册P413 */lcd_regs->lcdcon5 = (1<<11) | (0<<10) | (1<<9) | (1<<8) | (1<<0);/* 3.3 分配显存(framebuffer), 并把地址告诉LCD控制器 */s3c_lcd->screen_base = dma_alloc_writecombine(NULL, s3c_lcd->fix.smem_len, &s3c_lcd->fix.smem_start, GFP_KERNEL);lcd_regs->lcdsaddr1  = (s3c_lcd->fix.smem_start >> 1) & ~(3<<30);lcd_regs->lcdsaddr2  = ((s3c_lcd->fix.smem_start + s3c_lcd->fix.smem_len) >> 1) & 0x1fffff;lcd_regs->lcdsaddr3  = (240*16/16);  /* 一行的长度(单位: 2字节) *///s3c_lcd->fix.smem_start = xxx;  /* 显存的物理地址 *//* 启动LCD */lcd_regs->lcdcon1 |= (1<<0); /* 使能LCD控制器 */lcd_regs->lcdcon5 |= (1<<3); /* 使能LCD本身 */*gpbdat |= 1;     /* 输出高电平, 使能背光 *//* 4. 注册 */register_framebuffer(s3c_lcd);return 0;}static void lcd_exit(void){unregister_framebuffer(s3c_lcd);lcd_regs->lcdcon1 &= ~(1<<0); /* 关闭LCD本身 */*gpbdat &= ~1;     /* 关闭背光 */dma_free_writecombine(NULL, s3c_lcd->fix.smem_len, s3c_lcd->screen_base, s3c_lcd->fix.smem_start);iounmap(lcd_regs);iounmap(gpbcon);iounmap(gpccon);iounmap(gpdcon);iounmap(gpgcon);framebuffer_release(s3c_lcd);}module_init(lcd_init);module_exit(lcd_exit);MODULE_LICENSE("GPL");